The Celtics needed a game like this. They not only needed a win after losing two straight, they also needed a win on a night when they played well. That they were able to accomplish this by playing only one great quarter won’t make Doc Rivers completely happy, but he will take it. And that third quarter was pretty great.

In a 119-95 win over the Kings, the Celtics outscored their visitors 33-18 in the third quarter and shot 71 percent while turning it over only three times. Eight different Celtics scored in the quarter and no one had more than six points or five shots.

That’s how they want to play and for one night at least, Rivers’ message was heard.

WHAT WENT RIGHT

Paul Pierce sets the tone: The captain came out and delivered 25 points in 25 minutes on 10-for-14 shooting with six rebounds and three assists. Pierce had 15 of his points in the first quarter getting the Celtics off to a strong start. He was content to pick his spots after that initial outburst.

Third quarter run: The Celtics started off hot, but cooled a bit in the second quarter, allowing the Kings to hang around. They left little doubt in the third quarter opening up an 22-point lead. This was exactly what the Celtics needed because the Kings weren’t able to come back twice and the lead allowed Rivers to rest his starters.

Semih Erden to the rescue: Without Kevin Garnettand Jermaine O’Neal, and with Shaquille O’Neal dealing with foul trouble (see below), the Celtics needed Semih Erden and he responded with 10 points and a career-high eight rebounds in 33 minutes.

O’Neal hasn’t exactly endeared himself to the fans yet, but the fact remains that when he has played he has given the Celtics a much-needed shot blocking presence and superior depth at the center position. Without him the Celtics are seriously thin with Shaquille O’Neal only able to play about 20 minutes a night.

Rivers said he was ‘concerned’ about the latest development and he should be.

Shaq’s foul trouble: On Christmas Day, Shaquille O’Neal made reference to the refereeing abilities of Bob Delaney who fouled him out after just 22 minutes. It was probably just a coincidence, but Delaney whistled Shaq for an offensive foul giving him four early in the third quarter. Shaq played just 14 minutes, contributing two points and one rebound and continuing his string of forgettable games.

O’Neal didn’t play in the second half against in a blowout win over Toronto last Friday, but he played 21 minutes against the Rockets on Monday.

“I’m concerned,” Doc Rivers said. “He’s [played three] weeks now and a practice and his knee swelled up. First of all it has to be extremely frustrating for him because he worked his butt off to get back and he was playing well. And secondly, we all have common sense. That’s a concern. Why is this happening? We have to figure that out.”

Without Garnett and O’Neal the frontcourt depth behind starters Glen Davis and Shaquille O’Neal is down to rookies Semih Erden and Luke Harangody. Rivers is reluctant to play the two of them together, but he may not have a choice because he doesn’t like to play Shaq more than 20 minutes or so.

“In some ways you have no choice,” Rivers said. “It is tougher but we have to do it. At the end of the day [Shaq’s] not functioning well because of the extra minutes.”

The original prognosis for Kevin Garnett‘s return from a strained calf was two weeks. Now it appears that it will take a little longer. Garnett won’t play tonight against the Kings, as expected, but Doc Riverssounded pessimistic about whether Garnett would be ready to go Friday against the Bobcats. That puts Monday’s game with the Magic as the new target date.

“Eddie [Lacerte, the team’s trainer] and I talked about it yesterday and it will really depend on what we do [Thursday],” Rivers said. “My guess [for Friday] is no, because after that we have two days off. My thinking right now, unless he comes out and practices the whole practice and looks great, is probably off Friday too and then probably [play] Monday.”

Rivers is aware that people are questioning the nature of Garnett’s injury, but he insisted that nothing has changed except the timeline. “There’s no conspiracy here or anything like that,” Rivers said. “He’s just taking a little longer than we wanted it to, but it’s not a big deal.”

While Rivers insisted that he’s not concerned that the injury is worse than originally feared, he is concerned about Garnett’s mental state.

“With Kevin because he’s so emotional, you just want to make sure he doesn’t get down about stuff,” Rivers said. “That’s where I’m always concerned with him. Starting with the, ‘Why is this happening to me,’ stuff and you don’t want him to go there, because it’s not a bad injury. But he doesn’t like missing games.”

Rivers is worried that his team is getting too complacent. “We’ve won games where I didn’t think we were mentally ready to play the game, but we were mentally tough enough to fight through it and win the game,” Rivers said. “But we’ve also lost some games where we haven’t had that mental toughness.”

What concerned him most against Houston was that his team took too many shortcuts. They switched screens when they didn’t have to. They looked for the home run play when an easier one would have sufficed.

“We just got to stay on it,” Rivers said. “We are a veteran team that knows there’s another level that we can play at and we play at it at times. So we just got to stay on top of it.” The blame, he said, rested mainly with the starters.

Rivers is taking a calculated gamble that he can get his team back on track by whipping them into shape and refocusing their attention. You may recall that similar motivational tactics had no effect on last season’s Celtics. That, along with the injuries, made them an incredibly frustrating team throughout January, February and March.

This year, Rivers has said, is different. It has to be. On the same night they lost to the Rockets, the Miami Heat slipped passed the Celtics for the best record in the Eastern Conference. “I know they’re playing well, honest to gosh, I could care less,” Rivers said. “I am only concerned with our team.”

And he is concerned. Transition defense, pick and roll coverage, offensive execution, all these things must be corrected sooner rather than later and it needs to start tonight against the Kings.

Celtics president Danny Ainge doesn’t like to give timelines on when injured players will return to the court and there’s a good reason for that: Things change.

Take Kevin Garnett, for example. Late last week Doc Rivers suggested that Garnett would be back Monday or maybe Wednesday. That forecast no longer appears likely to materialize after the Celtics went through practice without Garnett on Tuesday.

“He’s just not ready yet,” Rivers said. “He’s close, very close. I think he wants to play, but I just don’t think he should play yet.”

That was probably the right call. Why take a chance in mid-January if you’re not 100 percent certain? But if he doesn’t play by Friday, expect a whole host of questions about the nature of Garnett’s injury, which has been described as a calf strain. Without the timeline, this is just a common-sense delay.

Then there’s Kendrick Perkins, who announced that he was ready to return to full-contact practice and would be back in three weeks. But when the Celtics held practice, Perkins was kept on the sidelines by Rivers and Dr. Brian McKeon for everything expect skeleton drills and no-contact running.

It was the team’s first practice in weeks and Rivers wanted it to be live and physical. In other words, it wasn’t a good environment for Perkins to take his first contact since injuring his knee in Game 6 of the NBA finals.

“We went pretty hard so I didn’t want him out there in that,” Rivers said. “We did a lot of contact stuff and I didn’t want him to be a part of it. It was a good practice actually. I knew we were going to do a lot of live, hard rebounding stuff. Too many bodies. Too many feet. I didn’t want him involved.”

Perkins, who will be kept out of live practice for the rest of the week, said he was disappointed, but he understood. “A little bit, but at the same time I know it’s in my best interest,” he said when asked if he was frustrated by the delay. “If they say one more week, I can go one more week.”

Still, Perkins wouldn’t back off his ultimate timeline to return in three weeks. If he can’t go by the time the Celtics play the Lakers on Jan. 30, then it will feel like a setback, he said — even though he is only six months removed from knee surgery.

Of all the injured Celtics, Delonte West has offered no set timetable. He had his hard cast taken off his broken right wrist, but he’s still not able to do anything basketball-related with his right hand like catch, shoot or dribble a ball. He also said he has trouble turning doorknobs in his house and carrying groceries.

In the meantime, West said he has watched Youtube videos of “karate masters” (his term) to learn how to absorb contact in other parts of his body when he falls. He also went to Home Depot and bought a bucket, which he filled with rice. He sticks his hand in the bucket and churns. (Hall of Fame pitcher Steve Carlton did the same routine for years.)

“It works too,” he said. “Try it man.”

West was vague when pressed for a return date, which was smart because he simply doesn’t know yet. His next step is to be able to handle the basketball with his right hand, which he hopes will happen next week. Ultimately he knows that his body will tell him when it’s time.

WALTHAM — Celtics forward Kevin Garnett did not take part in his team’s practice on Tuesday, and it is unlikely that he will play on Wednesday when the Celtics are scheduled to host Sacramento.

He’s just not ready yet,” Celtics coach Doc Rivers said. “He’s close, very close. I think he wants to play but I just don’t think he should play yet.”

The Celtics won’t have a shootaround before Wednesday’s game, which is another indication that Garnett won’t play against the Kings. “I doubt he plays. There’s a chance but I doubt it,” said Rivers, who called Garnett day-to-day.

Garnett has been out since suffering a left calf strain against the Pistons on Dec. 29. Including that contest, the Celtics are 4-4 without Garnett, and his absence was felt acutely by teammates during their 108-102 loss to the Rockets on Monday.

In 30 games this year, Garnett is averaging 15.0 points and 9.5 boards a game while shooting a career-best 53.9 percent from the floor.

First, Wallace’s agent Bill Strickland told Fanhouse’s Sam Amick that his client hasn’t changed his mind about his retirement (although Strickland did use the disclaimer, “for now.”) Second, Smith himself backtracked from the original claim saying Wallace told him he would return “monthsago.”

So, there’s not even smoke on this latest rumor, but even if Wallace did want to return to the Celtics, there are compelling reasons to believe that it won’t happen.

1. There is no room for Wallace figuratively

The Celtics have four centers — Shaquille O’Neal, Jermaine O’Neal, Semih Erden and Kendrick Perkins, who is expected to practice this week and has announced himself close to returning. All four have had injuries this season, which is why Danny Ainge has four centers on the roster.

“I know that he’s been in the locker room a couple of times this year and he’s been to a couple of practices. I know the guys are teasing him about that about coming back. He’s said that doesn’t want to come back. I’m not sure there’s room for Rasheed unless we just have a whole bunch of injuries. Right now our center position, we have three healthy centers, we have a fourth one that’s not too far away in Perk.” (Emphasis mine).

Ainge also said that he’s more concerned about his backcourt, which truly hinges on the health of Delonte West. The Celtics have come to the conclusion that Nate Robinson is not a viable candidate to replace Rajon Rondo should anything happen to him, which leaves West. The Celtics have centers. What concerns them is the depth at guard.

2. There is no room for Wallace literally

The Celtics have 15 players under guaranteed contracts. The deadline to release Von Wafer (and West) without having to pay them for the rest of the season has come and gone, which means that in order for the Celtics to add a player (like Wallace), someone would have to go either by trade or outright release.

Looking at the roster it would seem that adding another veteran big man is way down on their list of concerns.

3. The Celtics don’t view Wallace as a viable replacement for Kevin Garnett

Garnett isn’t likely to play Wednesday, but Doc Riversinsists that it’s only a matter of time and he is very close to getting back on the court. They also insist that Garnett’s injury is a muscle strain and has nothing to do with his knee.

Assuming that is the case, suppose Garnett suffers a more serious injury at some point, would adding Wallace make more sense? In a word, no.

In 2009-10 Wallace rarely played any position other than center. When he did play alongside Perkins up front, the Celtics weren’t very good, andRivers even said that he didn’t like playing the two of them together.

In sum: If one of the O’Neals suffered a season-ending injury and if Perkins isn’t able to make a full recovery from knee surgery, then there might be a fit for Wallace if he even wanted to come back. But that’s a lot of ifs.